pupeperson 5pts The difficulty has always been figuring out a way to lubricate the pintle in the injector. Gasoline is notoriously poor as a lubricant. No lubrication = too much heat = injector failure. Another problem with high pressure gasoline is that it is explosive if there is any air (oxygen) in the fuel supply -- like it begins to run out of fuel, sucks some air that hits a hot pump or injector pintle and the explosion happens in the wrong place at the wrong time. Not good. Diesel is it's own lubricant and requires a much larger quantity of air for combustion.